1. Field of the Invention
The present invention relates to an optical touch panel.
2. Description of the Related Art
Optical touch panels are widely used in, for example, bank ATM systems and railway ticket-vending machines because their reliability is high and their coordinate input region has a high transmittance and therefore can display sharp images. However, a conventional optical touch panel has a problem in that it cannot detect touches in environments where ambient light such as sunlight and light from lamps is strong because input to its light-receiving element becomes excessive.
In order to solve such a problem, there has been proposed an optical touch panel in which a light blocking member for preventing the entry of ambient light is provided above a light-emitting element line and a light-receiving element line arranged around a coordinate input region (see Japanese Unexamined Patent Publication No. 11-86698). However, the blockage of ambient light by the light blocking member is not yet sufficient, and therefore it remains difficult to use such an optical touch panel in environments with higher light levels such as outdoors.